Generation and use of integrated circuit profile-based simulation information

ABSTRACT

The invention includes a method and a system for generating integrated circuit (IC) simulation information regarding the effect of design and fabrication process decisions. One embodiment includes creating and using a data store of profile-based information comprising metrology signal, structure profile data, process control parameters, and IC simulation attributes.  
     Another embodiment is a method and system for generating a simulation data store using signals off test gratings that model the effect of an IC design and/or fabrication process. One application includes creation and use of a simulation data store generated using test gratings that model the geometries of the IC interconnects. The interconnect simulation data store may be used in-line for monitoring electrical and thermal properties of an IC device during fabrication. Other embodiments include methods and systems for generating and using simulation data stores utilizing a metrology simulator and various combinations of a fabrication process simulator, a device simulator, and/or circuit simulator. Information from the simulation data store may be used in-line in-situ during the design or fabrication process steps.

[0001] This application relates to co-pending U.S. patent applicationSer. No. 09/727,530 entitled “System and Method for Real-Time LibraryGeneration of Grating Profiles” by Jakatdar, et al., filed on Nov. 28,2000, owned by the assignee of this application and incorporated hereinby reference and to co-pending U.S. patent application Ser. No.09/764,780 entitled “Caching of Intra-Layer Calculations for RapidRigorous Coupled-Wave Analyses” by Jakatdar, et al., filed on Jan. 26,2000, owned by the assignee of this application and incorporated hereinby reference.

BACKGROUND OF INVENTION

[0002] 1. Field of Invention

[0003] The present application relates to the general area of integratedcircuit (IC) manufacture and more particularly to methods and systemsfor creating and using a data store of profile-based simulationsinformation.

[0004] 2. Related Art

[0005] With the demand for increasing clock rates and decreasinggeometries of IC structures, there is a need for rapid feedback on theeffect of wafer design and fabrication process decisions. In manytraditional IC manufacturing environments, the effect of a designdecision or a fabrication process change is frequently not immediatelyknown by the designers or the process engineers until much later,resulting in costly rework or unusable end products. IC designobjectives drive the design activity where masks and IC fabricationplans are produced and transmitted to IC fabrication. IC fabricationproduces the wafers that are tested and that undergo finishingoperations in IC testing and finishing where flaws or shortcomings ofthe wafer are noted. Typically, some of the impact of design or processdecisions is fed back to the design and fabrication groups at thispoint. After shipment of the products to the customers, additionalproduct feedback that relate to design and process alterationseventually get back to IC design. It is well known in the industry thatdetection of a bad chip at the wafer level is much cheaper thandetecting the bad chip after many end-products have been shipped to thecustomers. Thus, there is a need to provide information about the impactof design and process changes as early as possible.

[0006] In a similar manner, there is a dearth of immediate feedback ondesign and process decisions to the manufacturing process control group.FIG. 1 is a prior art architectural diagram illustrating the flow ofdata from IC manufacturing process control to the various fabricationareas and feedback from the fabrication areas to IC manufacturingprocess control. The IC manufacturing objectives 21 directs the ICmanufacturing process control 23 group with manufacturing plans 24related to thin film processes, deposition, or chemical mechanicalpolishing (CMP) 25, lithography 27, etching 29, photoresist (PR)stripping 33 and 35, implantation 31, and thermal processes 37 and ICtesting and packaging 39. Process feedback 34 and design and overallfabrication feedback 32 are sent to the IC manufacturing process control23 group. However, if a design did not produce the desired results or aprocess change caused some key critical dimension (CD) of the structuresto be out of the acceptable ranges, the batch of wafers affected mayhave to be discarded. Thus, there is a need to provide informationin-line to the IC manufacturing process control group in order tominimize rejected wafers and to detect and correct process controlparameters from drift or process control parameter variations. Even withthe use of current design and fabrication process simulators, there istypically insufficient information available early and/or in-line withthe fabrication process.

[0007] There are several fabrication process, device, and circuitsimulators currently in use. Examples include software capable ofinterconnect simulation, lithography simulation, implantationsimulation, diffusion simulation, oxidation simulation, deposition andetching simulation, CMP simulation, deposition and reflow simulation,2-dimensional process simulation, and 3-dimensional fabrication processsimulation, and others capable of simulating a step or series of stepsof the IC fabrication process. Some simulators assume simple geometricshapes of IC structures. However, data provided by AFM, Cross-SectionSEM (X-SEM), and optical metrology systems indicate the cross-sectionsof structures are complex shapes. These complex-shaped structuresprovide different electrical, thermal, and performance properties thanthe typical geometric shapes assumed. Other simulators attempt to modelcomplex shapes with limited success due to the number of variablesduring fabrication. For example, the structure shape is greatlyinfluenced by the process control parameters such as lithographynumerical aperture, wavelength, focus exposure, post exposure bake (PEB)temperature, resist thickness, anti-reflective coating thickness,dielectric materials, and fabrication processes used.

[0008] As technology heads into the deep submicron geometries, (0.025micron or less), there is a greater need for fast and accurateinformation relating to fabrication process attributes such as structureprofiles, device attributes such as capacitance, inductance, andresistance and ultimately circuit attributes. Similarly, there is a needfor fast and reliable information for process control parameters such asPEB temperature, focus, and exposure that generate the desired ICstructure profiles that in turn provide the desired device and circuitattributes. Thus, there is a need for a method and/or system for makingthe information on profile data, signals, process control parameters,and process attributes available during the fabrication process.Alternatively, given a structure profile or process attribute target,there is a need for rapid information on the process control parametervalues that would provide the desired results. For example, it isadvantageous to know the combination of PEB temperature, time, numericalaperture, and focus required to fabricate a structure with the desiredprofile that delivers the required electrical, thermal, and performanceproperties.

SUMMARY OF INVENTION

[0009] The invention includes a method and a system for creating andusing a data store of profile-based simulation information. Oneembodiment includes creating and using a data store of profile-basedinformation comprising signals measured by a metrology device, structureprofile data, process control parameters, and fabrication attributes.Information from the data store may be used in-line during the design orfabrication process and/or in-situ with the fabrication processequipments.

[0010] Another embodiment is a method of generating an interconnectsimulation data store using test gratings that model the geometries ofinterconnects for the IC. The interconnect simulation data store may beused in-line for monitoring electrical and thermal properties of an ICduring fabrication. Alternatively, the simulation data store serverprovides information about the process control parameters that wouldsatisfy the required electrical properties of interconnects in the ICdesign for a given fabrication process.

[0011] Still another embodiment includes a method and system forgenerating simulation data store utilizing a metrology simulator and afabrication process simulator. The fabrication process simulator maysimulate lithography, implantation, diffusion, oxidation,deposition-and-etching, CMP, deposition-and-reflow, 2-dimensionalprocess, 3-dimensional process simulator or combination of theseprocesses. Based on a range of process control parameters and deviationsof these process control parameters, structure profile data aregenerated using a fabrication process simulator. The simulated structureprofile data are converted into signals using the metrology simulator. Asimulation data store generator creates data store instances storingvariations of the process control parameters and associated signals,profile data, and fabrication attributes. Other embodiments includemethods and systems for generating simulation data store utilizing ametrology simulator and a combined process and device simulator or acombined process, device, and circuit simulator. Information from thesimulation data store may be used in-line in-situ with each fabricationprocess step, providing up-to-date pertinent information to improvedesign, fabrication steps, yield, or information to correct processdrifts.

BRIEF DESCRIPTION OF DRAWINGS

[0012]FIG. 1 is a prior art architectural diagram illustrating the flowof data from IC manufacturing process control to the various fabricationareas and feedback from the fabrication areas to IC manufacturingprocess control.

[0013]FIG. 2 is a prior art architectural diagram contrasting the layerfeature profile of actual lithography process steps versus the featureprofile typically generated in a lithography simulator.

[0014]FIG. 3 is a prior art architectural diagram contrasting theinterconnect cross-section of actual lithography and etching processsteps versus the typical interconnect cross-section generated in aninterconnect simulator.

[0015]FIG. 4 is an architectural diagram illustrating the use of anoptical metrology system to determine the profile of periodicstructures.

[0016]FIG. 5A is an architectural diagram illustrating the creation of asimulation data store using a device simulator in one embodiment of thepresent invention.

[0017]FIG. 5B is an architectural diagram illustrating the creation ofan interconnect simulation data store in one embodiment of the presentinvention.

[0018]FIG. 6A is an architectural diagram illustrating the creation of aprofile-based simulation data store using a fabrication processsimulator in one embodiment of the present invention.

[0019]FIG. 6B is an architectural diagram illustrating the creation of aprofile-based simulation data store using fabrication and devicesimulators in one embodiment of the present invention.

[0020]FIG. 6C is an architectural diagram illustrating the creation of aprofile-based simulation data store using process fabrication, device,and circuit simulators in one embodiment of the present invention.

[0021]FIG. 7A is an architectural diagram illustrating inquiry andin-line use of a simulation data store in one embodiment of the presentinvention.

[0022]FIG. 7B is an architectural diagram illustrating in-situ use of asimulation data store in various fabrication steps in one embodiment ofthe present invention.

[0023]FIG. 8A is a flow chart of the operational steps for creation of aprofile-based simulation data store using profile library data in oneembodiment of the present invention.

[0024]FIG. 8B is a flow chart of the operational steps for creation of aprofile-based simulation data store using test gratings in oneembodiment of the present invention.

[0025]FIG. 9A is a flow chart of operational steps for in-situutilization of a profile-based simulation data store in one embodimentof the present invention.

[0026]FIG. 9B is a flow chart of operational steps for online inquiryutilization of a profile-based simulation data store in one embodimentof the present invention.

[0027]FIG. 10 illustrates a data store format of profile-basedsimulation data store in one embodiment of the present invention.

[0028]FIG. 11A is a graph showing the correlation of optical metrologyCD and the difference ΔW of the electric CD from the mask CD.

[0029]FIG. 11B are two graphs showing less variation of bottom CD andfeature sidewall angle for a full-profile monitored fabrication processcompared to CD monitored or no monitoring of profile.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENT(S)

[0030] The invention includes a method and a system for creating andusing a data store of profile-based simulation information. FIGS. 2 and3 illustrate the differences between simulation profiles versus actualprofiles of structures. FIGS. 4 to 8C depict embodiments of the creationprocess for the profile-based simulation data store. FIGS. 9A and 9Bdepict embodiments for using the profile-based simulation information.FIG. 10 illustrates one format of the simulation data store, while FIGS.11A and 11B represents empirical data that illustrate the utility of theconcepts and principles of the present invention.

[0031]FIG. 2 is a prior art architectural diagram contrasting the layerfeature profile of actual lithography process steps versus the featureprofile generated in a typical lithography simulator. A lithographysimulator 73 simulates the actual physical processes including spin/coat61, soft bake 63, exposure 65, post exposure bake 67, and development 69processes. The actual structure profile 71 may have a more complexprofile such as a rounded top and a footing at the bottom of thefeature, not the ideal rectangular shaped design structure profile 75typically indicated by the lithographic simulator 73. The electricalproperties of a circuit with non-rectangular structures, such astrapezoids, T-tops, and T-tops with undercut, rounded tops, with orwithout footing, are different from the electrical properties of simplegeometric-shaped structures typically assumed in some fabricationprocess simulators.

[0032] Similarly, FIG. 3 is a prior art architectural diagramcontrasting the interconnect cross-section of actual lithography,etching, and metallization process steps versus the interconnectcross-section generated in a typical interconnect simulator. Thefabricated interconnect cross-section 87 produced after the steps ofinterconnect design 81, fabrication 83, and testing 85 is typicallyirregular in shape. The shape of the fabricated interconnect is affectedby the geometries of the conductive material and the related dielectricmaterial. Electrical and thermal characteristics of the interconnectstructure with the fabricated interconnect cross-section 87 aredifferent from the electrical and thermal characteristics of arectangular design interconnect cross-section 91 typically assumed byinterconnect simulators 73. Given the current drive towards deepsubmicron process technologies and increasing clock rates, interconnectsessentially control the overall operating performance of high-speedsystems. The geometries of interconnects have significant impacts on theelectrical performance of the IC. Although atomic force microscopes(AFM) can provide interconnect profile information, AFM's are slow andcannot provide information on unpattemed layers. Critical dimensionscanning electron microscopes (CD-SEM) can provide critical dimensionsbut cannot provide profile information or data about unpattemed layers.

[0033] In order to facilitate the description of the present invention,an optical metrology system is used to illustrate the concepts andprinciples. It is understood that the same concepts and principlesequally apply to the other IC metrology systems as will be discussedbelow. The metrology system may be an optical, electric, electron, ormechanical metrology system. Examples of optical metrology systemsinclude scatterometric devices such as spectroscopic ellipsometers,reflectometers, and the like. Examples of electron metrology systemsinclude CD-scanning electron microscope (CD-SEM), transmission electronmicroscope (TEM), and focused ion beam (FIB) devices. An example of amechanical metrology system includes an atomic force microscope (AFM)whereas an example of an electric metrology system includes acapacitance-measuring unit. As used in this application, a metrologysignal may be an optical signal, an ion beam, an electron beam, or otherlike signals.

[0034]FIG. 4 is an architectural diagram illustrating the use of anoptical metrology system to determine the profile of periodicstructures. The optical metrology system 40 includes a metrology signalsource 41 projecting a signal 43 at the target periodic structure 53 ofa wafer 47 mounted on a metrology platform 55. The metrology signal 43is projected at an incidence angle θ towards the target periodicstructure 53. The reflected signal 49 is measured by a metrology signalreceiver 51. The reflected signal data 57 is transmitted to a metrologyprofiler system 59. The metrology profiler system 59 compares themeasured reflected signal data 57 against a library of calculatedreflected signal data representing varying combinations of criticaldimensions of the target periodic structure and resolution. The libraryinstance best matching the measured reflected signal data 57 isselected. The profile and associated critical dimensions of the selectedlibrary instance correspond to the cross-sectional profile and criticaldimensions of the features of the target periodic structure 53. Asimilar optical metrology system 40 is described in co-pending U.S.patent application Ser. No. 09/727,530 entitled “System and Method forReal-Time Library Generation of Grating Profiles” by Jakatdar, et al.,filed on Nov. 28, 2000, owned by the assignee of this application andincorporated herein by reference.

[0035]FIG. 5A is an architectural diagram illustrating the creation of asimulation data store using a device simulator in one embodiment of thepresent invention. The profile-based creation of a simulation data store100 includes a fabrication process designer 101 where the series of ICfabrication steps are laid out. A set of test grating masks is designedin the test grating mask designer 103 to capture key features orcharacteristics of the area of interest. For example, if the area ofinterest is capacitance of interconnects, then the set of test gratingmasks designed captures the various interconnect geometric information.Interconnect geometric information include profiles of structures in thewafer. The IC fabricator 105 uses the set of test grating masks to maketest structures that are measured by a metrology device 107. Themetrology device 107, which may be an optical metrology device or anon-optical metrology device, measures the signals off the test gratingsand transmits the measured signals to the profiler application server109. The profiler application server 109 compares the measured signalsoff the test structures to the calculated signals in a profile library110 covering a range of expected structures profile critical dimensionsand resolutions. The profiler application server 109 selects the bestmatching profile library instance from the calculated signals of theprofile library 110. In one embodiment, the best matching measureddiffracted metrology signal is one with the least error compared to thediffracted metrology signal. Several optimization procedures areavailable to minimize the error, such as simulated annealing, describedin “Numerical Recipes,” section 10.9, Press, Flannery, Teulkolsky &Vetterling, Cambridge University Press, 1986; which is incorporated byreference. One error metric that produces appropriate results is thesum-of-the-squared-difference error, where the optimization procedureminimizes the error metric between the measured diffracted metrologysignal and the calculated diffracted metrology signal. The detailedprocedure for creating calculated signals for a profile library for arange of structure profile critical dimensions and resolutions andselecting the best matching library instance from the calculated signalslibrary is contained in co-pending U.S. patent application Ser. No.09/727,530 entitled “System and Method for Real-Time Library Generationof Grating Profiles” by Jakatdar, et al., filed on Nov. 28, 2000, and isincorporated herein in its entirety by reference.

[0036] Still referring to FIG. 5A, the profile data of the best matchingprofile library instance are transmitted to the device simulator 113.Profile data comprises critical dimensions, profile shape description,and profile graphic representation. Critical dimensions are typicallyexpressed as measurement dimensions, for example, width of 50nanometers. Alternatively, critical dimensions are also expressed as apercent of another critical dimension, for example, 80% height of toprounding meaning the structure top starts rounding at 80% of thestructure's height. An example of profile shape description istrapezoidal with top rounding profile. An example of profile graphicrepresentation is a bit map of the profile. The device simulator 113 maybe any type of device simulator simulating electrical, thermal, noise,3D effects, steady or transient state signal, leakage and/or opticalcharacteristics. Examples of device simulators are Raphael.TM,Medici.TM, ATLAS.TM, and TMA-Visual.TM from companies such as Avant!,Technology Modeling Associates, and Silvaco International. The profilecritical dimensions of the best matching library instance from thecalculated signals library is extracted by the profiler applicationserver 109 and transmitted to the device simulator 113. The devicesimulator 113 creates as output the set of process control parametersused in the simulation run and the resulting device attributes. Forexample, if the device simulator is an interconnect simulator, the inputmay be the top and bottom CD's in nanometers, and the sidewall angle indegrees in a format required by the interconnect simulator used. Theoutput of the device simulator 113 is device attributes includingresistance in ohms, capacitance in farads, and inductance in henrys. Thesimulation data store generator 111 creates a data store instancecomprising signals, profile data, simulation type, and device attributesassociated with the specific device simulation. Simulation type is thecharacterization of the simulation being performed, for example devicesimulation. A partial list of simulation types is included in FIG. 10.

[0037]FIG. 5B is an architectural diagram illustrating the creation ofan interconnect simulation data store in one embodiment of the presentinvention. The profile-based creation of a simulation data store 120includes a fabrication process designer 121 where the series of ICinterconnects are laid out. A set of test grating masks is designed inthe test grating mask designer 123 that captures the variousinterconnect geometric information. Interconnect geometric informationinclude profiles of structures in the wafer. The IC fabricator 125 usesthe set of test grating masks to make test structures that are measuredby a metrology device 127. The metrology device 127, which may be areflectometer, an ellipsometer or other non-optical metrology device,measures the diffracted signals off the test structures and transmitsthe measured signals to the profiler application server 129. Theprofiler application server 129 compares the measured signals off thetest structures to the calculated signals in a library 130 covering arange of expected structures profile critical dimensions andresolutions. The profiler application server 129 selects the bestmatching library instance from the library. The profile CD's of the bestmatching library instance is extracted by the profiler applicationserver 129 and transmitted to the interconnect simulator 133. Theinterconnect simulator 133 creates as output the set of process controlparameters used in the simulation run and the device attributes.Examples of interconnect simulators include Raphael.TM, QuickCap.TM, andAtlas.TM. The output of the interconnect simulator 133 includes deviceattributes such as resistance in ohms, capacitance in farads, andinductance in henrys. The simulation data store generator 131 creates adata store instance in the simulation data store 135 for each testgrating comprising signals, profile data, simulation type, and deviceattributes. Simulation type is this case is interconnect devicesimulation and the device attributes are those associated with theinterconnect device simulation. An illustrative layout of simulationdata store is depicted in FIG. 10.

[0038] For FIG. 6A to 6C, similar figure objects are identified with thesame numbers in order to facilitate the description of the embodiments.FIG. 6A is an architectural diagram illustrating the creation of aprofile-based simulation data store using a fabrication processsimulator in one embodiment of the present invention. The profile-basedcreation of a simulation data store 130 starts with the input of processcontrol parameters 132 into the fabrication process simulator 133.Examples of process control parameters include exposure time, numericalaperture, and PEB temperature in a lithographic process simulation. Thefabrication process simulator 133 may be any type of process simulatorsimulating a thin film, lithography, implantation, diffusion, oxidation,deposition, etching, CMP process or combination of processes. Using theprocess control parameters 132, the fabrication process simulator 133creates the fabrication attributes 134 including the geometries of thelayer structures. The process control parameters 132 and fabricationattributes 134 are transmitted to the simulation data store generator139. The fabrication attributes 134 are transmitted to the metrologysimulator 137. Fabrication attributes that pertain to the profiles ofthe structures are used by the metrology simulator 137 to generatediffracted signals corresponding to the profile of the structuregenerated by the fabrication process simulator 133. For example, thefabrication process simulator 133 may be a lithography, etch, or acombined lithography and etch simulator. The process control parameters132 may include film thickness, bake time, exposure, PEB time, PEBtemperature, rinse time, and/or etch flow rate and type of etchant.Fabrication attributes 134 may include the patterned structure profileshape and critical dimensions (CD's) such as top CD, bottom CD, height,and/or sidewall angle.

[0039] Still referring to FIG. 6A, from the fabrication attributes 134,the metrology simulator 137 extracts the profile data and calculatessignals corresponding to the signals off a grating with the transmittedprofile shape and CD's. In a case where the metrology simulator 137 isan optical metrology simulator, the signals are simulated diffractionsignals. For a description of the calculation of simulated diffractionsignals, refer to co-pending U.S. patent application Ser. No. 09/764,780entitled “Caching of Intra-Layer Calculations for Rapid RigorousCoupled-Wave Analyses” by Jakatdar, et al., filed on Jan. 26, 2000,which is incorporated in its entirety herein by reference. Thesimulation data store generator 139 processes the process controlparameters 132 and input data from the fabrication process simulator 133and the metrology simulator 137 to create the simulation data store 149instances. The simulation data store instance comprises signals, profiledata, simulation type, process control parameters, and fabricationattributes associated with the process simulation. Simulation type isthe characterization of the simulation being performed, for thisexample, fabrication process simulation. A partial list of simulationtypes is included in FIG. 10.

[0040]FIG. 6B is an architectural diagram illustrating the creation of aprofile-based simulation data store using fabrication and devicesimulators in one embodiment of the present invention. The profile-basedsystem for creating the simulation data store 140 using a processsimulator and a device simulator is similar to the process described forFIG. 6A except that the output from the fabrication process simulator133 including fabrication attributes is also transmitted to a devicesimulator 135. The device simulator 135 utilizes the fabricationattributes to perform a device simulation and transmits deviceattributes 136 to the simulation data store generator 139. Thesimulation data store generator 139 processes the input data from thefabrication process simulator 133 comprising process control parameters132 and fabrication attributes 134, data from the metrology simulator137 comprising calculated diffracted signal 142, and data from thedevice simulator 135 comprising device attributes 136 to create thesimulation data store 149. The simulation data store 149 instancescomprises signals, profile data, simulation type, process controlparameters, fabrication attributes, and device attributes. Simulationtype in this case is a combined fabrication-process-and-devicesimulation. For example, the fabrication process simulator may be acombined lithography-and-etch process simulator whereas the devicesimulator may be an interconnect simulator. Other devices that may besimulated include diodes, transistors, optical devices, power devices,or photo detectors. An illustrative layout of simulation data store isdepicted in FIG. 10. The simulation data store for this example would beable to provide responses to several types of queries with a given data.If the given data is the desired capacitance of a device, the simulationdata store can provide the required profile(s) of the interconnects.Similarly, if the given data is a profile of the interconnect, thesimulation data store can provide the corresponding process controlparameters such as numerical aperture, bake time, PEB temperature, etchtime or type of etchant. Many other variations of the given datadiscussed later can be formulated to give the desired query response.

[0041] Still referring to FIG. 6B, the fabrication process simulator 133and the device simulator 135 may be separate objects or combined in asingle object or a single software package. Examples of combined processand device simulators include Victory.TM from Silvaco International andMicrotec.TM from Syborg Systems, Inc.

[0042]FIG. 6C is an architectural diagram illustrating the creation of aprofile-based simulation data store using fabrication process, device,and circuit simulators in one embodiment of the present invention. Theprofile-based system for creating the simulation data store 150 using afabrication process simulator, a device simulator, and a circuitsimulator is similar to the process described for FIG. 6B except thatthe output from the device simulator 135 including device attributes 136are also transmitted to a circuit simulator 141. The circuit simulator141 utilizes the device attributes of several devices that form thecircuit. For example, a transmission line includes several interconnectdevices to form a circuit. Examples of circuits that may be simulatedinclude transmission lines, resistors, capacitors, inductors,amplifiers, switches, diodes, or transistors. The combination ofselected devices to form a circuit are simulated, the simulationscreating device attributes 136 that are used to perform a circuitsimulation with the circuit simulator 141. The circuit simulator 141generates and transmits circuit attributes 138 to the simulation datastore generator 139. The simulation data store generator 139 processesthe input data from the fabrication process simulator 133 comprisingprocess control parameters 132 and fabrication attributes 134, data fromthe metrology simulator 137 comprising calculated diffracted signal 142,and data from the device simulator 135 comprising device attributes 136,and data from the circuit simulator 141 comprising circuit attributes138 to create the simulation data store 149. The simulation data store149 instance comprises signals, profile data, simulation type, processcontrol parameters, fabrication attributes, device attributes, andcircuit attributes. Simulation type is the characterization of thesimulation being performed, for this example, combined fabricationprocess, device, and circuit simulation. A partial list of simulationtypes is included in FIG. 10.

[0043] Still referring to FIG. 6C, the fabrication process simulator133, device simulator 135, and circuit simulator 141 may be separateobjects or combined in a single object or a single software package.Examples of circuit simulators include SPICE.TM, various adaptations ofSPICE.TM, SPECTRE.TM, APLAC.TM, and PROTOLAB.TM. An example of acombined total process simulator is ATHENA.TM from SilvacoInternational.

[0044] The concepts and principles of the present invention will applyto other combination simulators such as a combined device-and-circuitsimulation. Creation of the simulation data store would be done in asimilar manner. Similarly, the device simulator and circuit simulatormay be separate objects or combined in a single object or a singlesoftware package. Examples of combined device-and-circuit simulatorsinclude MEDICI.TM, TOPSPICE.TM, CIDER.TM, and SIMPLORER.TM.

[0045]FIG. 7A is an architectural diagram illustrating inquiry andin-line use of a simulation data store in one embodiment of the presentinvention. An inquiry 203 from an inquiry device 201 is transmitted to asimulation data store server 207 that analyzes the inquiry and accessesthe instance(s) of the simulation data store 215 and formulates theresponse 205. The simulation data store server 207 may also be invokedby an in-line query 209 generating a response 209. In one application,the inquiry 209 is from an in-line query device 211 generating aresponse 213. The inquiry 209 comprises the type of inquiry and querygiven data. Depending on the type of inquiry and query given data, thesimulation data store server 207 retrieves the appropriate instance(s)of the simulation data store 215 and formats and transmits the response213. The in-line query device 211 may be part of a computer system orpart of an IC fabrication system. The inquiry device 201 may be astand-alone device or part of a system. Furthermore, the inquiry device201 may be local or accessible through a network.

[0046]FIG. 7B is an architectural diagram illustrating the in-situ useof a simulation data store in various fabrication steps in oneembodiment of the present invention. A simulation data store server 250coupled to a simulation data store 255 may be part of a fabricationsystem, the simulation data store server 250 providing immediate in-situprofile-based simulation information. The simulation data store server250 may be coupled to a thin film, deposition or CMP 225, lithography227, etch 229, PR stripping after etch 233, PR stripping afterimplantation 235, implantation 231, and/or thermal processes 237devices. The simulation data store server 250 may be locally or remotelyconnected to the fabrication devices. The simulation data store server250 may be several separate servers or one centralized server. Teststructures or test gratings in a wafer may be measured by an integratedmetrology device (not shown) during or after a fabrication step. Themetrology measurement generates measured signals that may be used as thequery given data to the simulation data store server 250. The simulationdata store server 250 generates an in-situ/in-line response based on theinquiry type and query given data. For example, during or after aphotoresist stripping step, if the inquiry type from the fabricationdevice is for electrical properties of the IC structure modeled by thetest grating and the query given data is the diffracted signal off thetest grating, the simulation data store server 250 would formulate aresponse comprising conductance, capacitance, and/or resistance of theIC structure modeled by the test grating. In another example after alithography step, if the inquiry type is for process control parametersassociated with the measured signals off the test grating, thesimulation data store server 250 would formulate a response comprisingbake time, bake temperature, focus, and PEB time and temperature. Aswill be discussed below, many other combinations of inquiry type andquery given data can be transmitted to the data store server 250 to getthe specific response required.

[0047]FIG. 8A is a flow chart of the operational steps for creation of aprofile-based simulation data store using profile library data in oneembodiment of the present invention. The expected profile data rangesand resolutions of profile shapes of patterned structures for theprofile library are determined 300. For example, a trapezoidal profileshape may be characterized by the top CD, bottom CD, grating thickness,height and width at the inflection point, and underlying thickness innanometers. The profile data ranges would include a minimum, maximum,and resolution for the top CD, bottom CD, grating thickness, height andso on. The profile data ranges at various resolutions of profile shapesare used to calculate the simulated diffracted signals and to create theprofile library 320. The detailed procedure for creating a profilelibrary for a range of structure profile critical dimensions andresolutions is contained in co-pending U.S. patent application Ser. No.09/727,530 entitled “System and Method for Real-Time Library Generationof Grating Profiles” by Jakatdar, et al., filed on Nov. 28, 2000 isincorporated herein in its entirety by reference.

[0048] The profile data ranges for the expected profile shapes areconverted into the device simulator input 330. For example, if thedevice simulator is an interconnect simulator, the expected profileshape dimensions are converted into the format required by the selectedinterconnect simulator, like Raphael.TM. Using the converted devicesimulator input, the device simulator is invoked 350 generating thedevice attributes. Continuing with the interconnect simulator example,the interconnect simulator is invoked using the converted profile dataas the interconnect simulator input, generating device attributescomprising electric and thermal properties such as resistance,capacitance, inductance, potential, temperature, and current densitydistribution. A simulation data store instance is created comprisingdiffracted signals, profile data, simulation type, and device attributes360. Again continuing with the interconnect example and assuming anoptical metrology device, the simulation data store instance createdincludes signals such as tangent (Ψ) and cosine (Δ) data for awavelength range for an ellipsometer or reflected light intensity for awavelength range for a reflectometer, the wavelength range andmeasurement points dependent on the manufacturer of the opticalmetrology device. In addition, the simulation data store instancecreated also includes the associated profile data comprising profileshape CD's, simulation type being interconnect device simulation,profile data comprising top CD, bottom CD, grating thickness, height andwidth at inflection point, and underlying thickness; and deviceattributes such as resistance, capacitance, inductance, potential,temperature, and current density distribution. The simulation data storecreation process is iterated until the simulations are complete 370.

[0049]FIG. 8B is a flow chart of the operational steps for creation of aprofile-based simulation data store using test gratings in oneembodiment of the present invention. The set of process controlparameters for the type of simulations desired is selected 400. Usingthe selected set of process control parameters, the fabrication processsimulator is invoked 410, generating fabrication attributes. Thefabrication attributes are converted into profile data comprisingprofile shape and critical dimensions 420. A metrology simulator usesthe profile shape and critical dimensions to calculate diffractedsignals 430. Data including the process control parameters, the profiledata, the calculated signals are used to create a simulation data storeinstance 435. For example, if the type of fabrication process simulationis lithography, the set of process control parameters may include valuesof the bake time, bake temperature, focus, PEB time, and/or rinsetemperature. The fabrication attributes generated by the fabricationprocess simulation include profile data, comprising profile shape andgeometry of the structure. The profile shape and geometry is convertedinto the CD's required by the metrology simulator to calculate thereflected signals. If the profile shape is trapezoidal profile with toprounding and bottom footing, the CD's include the feature footing bottomwidth, trapezoidal bottom width, total height, trapezoidal width, andthe rounding top width.

[0050] Fabrication attributes generated by the fabrication processsimulator are converted to the format compatible with the devicesimulator requirements 440. The device simulator is invoked using theconverted fabrication attributes, generating device attributes 445. Thesimulation data store instances are updated with the device attributes450. In one embodiment, the fabrication process simulator and the devicesimulator are combined in a single package, removing the requirement ofconversion of input parameters into compatible formats. Several devicesthat form a circuit or part of a circuit may be grouped together for acircuit simulation. For example, several IC components such as gates,contact holes, vias, and pads forming a circuit or part of a circuit aregrouped together for a circuit simulation. Device attributes for each ofthese grouped devices are converted into a format compatible with thecircuit simulator requirements 460. The circuit simulator is invoked,using the converted device attributes, generating circuit attributes465. Examples of circuit attributes are voltage and current as functionof time, noise analysis, distortion analysis, and sensitivity analysis.The appropriate simulation data store instances are updated with thecorresponding circuit attributes 470.

[0051]FIG. 9A is a flow chart of operational steps for in-situutilization of a profile-based simulation data store in one embodimentof the present invention. The signals off the test gratings of a waferare measured with a metrology device 600. A best matching signalinstance in the profile-based simulation data store is selected 610. Thesimulation type is determined 620 in order to access the simulation dataassociated with the best matching simulation data store instance 630.The requested information from the profile-based simulation data storeis displayed 640. Process control parameters, signals, profile data,fabrication attributes, device attributes, and/or circuit attributes maybe displayed.

[0052] For example, test gratings in a wafer after a lithography andetch process are measured with an optical metrology device, generatingmeasured diffracted spectra. The best matching instances of thesimulation data store compared to the diffracted spectra of the testgratings are selected and profile data of the test gratings areextracted. The requested information comprises electrical deviceattributes associated with an interconnect device simulation.Capacitance, resistance, and inductance information from the simulationdata store corresponding to the profile data of the test gratings aredisplayed.

[0053]FIG. 9B is a flow chart of operational steps for online inquiryutilization of a profile-based simulation data store in one embodimentof the present invention. The type of inquiry and query given data isvalidated against the profile-based simulation data store 700. Instancesof the profile-based simulation data store meeting the inquiry type andquery given data are selected 720. The requested information from theselected instances of the profile-based simulation data store isdisplayed 730. For example, if the inquiry type is for process controlparameters of a lithography simulation and the query given data iselectrical conductivity, displayed information may include profile CD'sand data on the focus, exposure, PEB temperature, resist thickness, andanti-reflective coating thickness for the lithography process.Conversely, if the inquiry type is for device attributes and the querygiven data are diffracted signals, displayed information may includecapacitance and other device attributes. Alternatively, if the inquiryis for profile data of a via and the query given data consists ofvoltage and current as a function of time for a circuit, the displayeddata may include the profile shape and CD's of the profile. It isunderstood that a person knowledgeable in the art can formulate a numberof different inquiry types and various combinations of query given datato get the right information displayed from the profile-based simulationdata store.

[0054]FIG. 10 illustrates a simulation data store format of aprofile-based simulation data store in one embodiment of the presentinvention. Data store format 800 includes signals 801, profile data 803,simulation data segments 804 comprising simulation type 805, processcontrol parameters or input parameters 807, and fabrication, device,and/or circuit attributes 809. For a given signal 801 and correspondingprofile data 803, there may be several simulation data segments 804 ofsimulation type 805, process control parameters or input parameters 807,and fabrication, device, and/or circuit attributes 809. Simulation type805 includes fabrication process simulation, device simulation, circuitsimulation, combined fabrication and device simulation, combined deviceand circuit simulation, or combined fabrication, device, and circuitsimulation. Examples of fabrication process simulation includelithography, etch, implantation, oxidation, CMP, diffusion, depositionand etching, deposition and reflow, 2-dimensional process, 3-dimensionalprocess simulations, plus various combinations of the foregoingprocesses. Examples of device simulation include interconnect,electrostatic discharge, optical device, power device, compound device,and other device simulations. Examples of circuit simulation includetransient signal, signal integrity, noise, and other circuit simulation.

[0055]FIG. 10 illustrate examples of simulation data store format for aninterconnect device simulation and a combined fabrication process anddevice simulation. In Example 1, an interconnect device simulation, thesignal is expressed in values representing optical metrology measurementdata using an ellipsometer. This example has one simulation data segmentwhere the key input parameter is profile data and the device attributesare capacitance, inductance, and resistance. Example 2 represents asimulation data store instance storing data from two linked simulations,namely, a lithography and etch fabrication process simulation linked toan interconnect device simulation. Each simulation has a correspondingsimulation data segment. The fabrication process simulation generatedthe fabrication attributes that are used as input to the devicesimulation. It is understood that to one knowledgeable in the art, thevarious combinations of fabrication process, device, and circuitsimulations would result in corresponding combinations of simulationdata segments following the same concepts and principles illustrated inthe foregoing examples.

[0056]FIG. 11A is a graph showing the correlation of optical metrologyCD and the difference ΔW of the electric CD from the mask CD. TheCD_(OPTICAL METROLOGY) is the critical dimension of a structure asdetermined by an optical metrology device such as an ellipsometer or areflectometer. CD_(MASK) is the critical dimension designed in a mask,such as top CD of a structure. CD_(ELECTRIC) is the critical dimensionof the structure based on the electrical properties and is derivedstarting with the basic equation: V/I=R where V is the voltage, I is thecurrent, and R is the resistance. The resistance R is equal toresistivity p divided by the area A:

R=ρ/A=ρ/H*CD _(ELECTRIC)

[0057] where H is the height of the structure and CD_(ELECTRIC) is theeffective width. Given that the resistivity ρ of a structure materialand H are generally constant, CD_(ELECTRIC) is the variable thatcontrols the electrical resistance of the structure. The graph 811 inFIG. 11A shows close correlation of optical metrology CD to ΔW, thedifference between the electric CD from the mask CD, the weightedaverage graph being a straight line. This empirical data illustrates theutility of profile-based simulation data stores as described in thevarious embodiments.

[0058]FIG. 11B are two graphs showing less variation of bottom CD andfeature sidewall angle for a full-profile monitored fabrication processcompared to CD-only monitored or no profile monitoring of thefabrication process. Empirical data obtained using an exponentiallyweighted moving average controller and first order integrated movingaverage disturbance generator indicate that full-profile control 821 ofthe bottom CD in a lithographic simulation provided the least variationsof bottom CD compared to CD-only control 825 or no control 823 shown inthe top graph. Similarly, the bottom graph based on empirical dataindicate that full-profile control 835 of the sidewall angle in alithographic simulation provided the least variations of sidewall anglecompared to CD-only control 833 or no control 831. Similar to FIG. 11A,these graphs that are based on empirical data illustrate the utility ofprofile-based simulation data stores as described in the variousembodiments.

[0059] There are many uses for a profile-based simulation data store inIC manufacturing. The concepts and principles of the present inventionare applicable to simulations of IC fabrication process steps, devices,or circuits. As will be apparent to a person knowledgeable in the art,the concepts and principles of creating and using a profile-basedsimulation data store also applies to combinations of fabricationprocess and device simulations, device and circuit simulations, orfabrication process, device, and circuit simulations.

[0060] Foregoing described embodiments of the invention are provided asillustrations and descriptions. They are not intended to limit theinvention to precise form described. In particular, it is contemplatedthat functional implementation of invention described herein may beimplemented equivalently in hardware, software, firmware, and/or otheravailable functional components or building blocks.

[0061] Other variations and embodiments are possible in light of aboveteachings, and it is thus intended that the scope of invention not belimited by this Detailed Description, but rather by Claims following.

We claim:
 1. A method of creating a profile-based simulation data storefor an integrated circuit utilizing one or more simulations, the methodcomprising: simulating one or more fabrication processes using aselected set of process control parameters, the fabrication processsimulations generating fabrication attributes; generating calculatedsignals with a metrology simulator, the metrology simulator usingprofile data from the fabrication attributes, the profile datacomprising profile shapes and critical dimensions of structuresresulting from the one or more fabrication process simulations; andcreating simulation data store instances, the instances includingprofile data and corresponding calculated signals, simulation types, andassociated process control parameters and fabrication attributes;wherein the simulation types are characterizations of the one or moresimulations performed.
 2. The method of claim 1 wherein simulating oneor more fabrication processes comprises: simulating a thin film,deposition or chemical mechanical polishing process using a selectedfirst set of process control parameters; and simulating lithographyprocess using a selected second set of process control parameters. 3.The method of claim 1 wherein simulating one or more fabricationprocesses comprises: simulating a lithography process using a selectedfirst set of process control parameters; and simulating an etch processusing a selected second set of process control parameters.
 4. The methodof claim 1 wherein simulating one or more fabrication processescomprises: simulating a lithography process using a selected first setof process control parameters; and simulating an implantation processusing a selected second set of process control parameters.
 5. The methodof claim 1 wherein simulating one or more fabrication processescomprises: simulating an etch process using a selected first set ofprocess control parameters; and simulating a photoresist strippingprocess using a selected second set of process control parameters. 6.The method of claim 1 wherein simulating one or more fabricationprocesses comprises: simulating an implantation process using a selectedfirst set of process control parameters; and simulating a photoresiststripping process using a selected second set of process controlparameters.
 7. A method of creating a profile-based simulation datastore for an integrated circuit utilizing one or more simulations, themethod comprising: simulating one or more devices using a selected setof input parameters, the device simulations generating deviceattributes, the set of input parameters including profile datacorresponding to the one or more simulated devices; generatingcalculated signals with a metrology simulator, the metrology simulatorusing profile data corresponding to the one or more simulated devices;and creating simulation data store instances, the instances includingprofile data and corresponding calculated signals, simulation types,process control parameters, and fabrication attributes; wherein thesimulation types are characterizations of the one or more simulationsperformed.
 8. The method of claim 7 wherein the selected set of inputparameters comprises a profile library having profile data, the profiledata including profiles of the one or more devices simulated.
 9. Amethod of creating a profile-based simulation data store for anintegrated circuit utilizing one or more simulations, the methodcomprising: simulating one or more circuits using a selected set ofinput parameters, a circuit having one or more devices, the circuitsimulations generating circuit attributes, the set of input parametersincluding profile data corresponding to the one or more devices of thesimulated one or more circuits; generating calculated signals with ametrology simulator, the metrology simulator using profile datacorresponding to the one or more devices of the simulated one or morecircuits; and creating simulation data store instances, the instancesincluding calculated signals, profile data, simulation types, processcontrol parameters, and circuit attributes; wherein the simulation typesare characterizations of the one or more simulations performed.
 10. Themethod of claim 9 wherein the one or more circuits simulated includetransmission lines, resistors, capacitors, inductors, amplifiers,switches, diodes, or transistors.
 11. A method of creating aprofile-based simulation data store for an integrated circuit utilizingone or more simulations, the method comprising: simulating one or morefabrication processes using a selected set of process controlparameters, the fabrication process simulations generating fabricationattributes; generating calculated signals with a metrology simulator,the metrology simulator using profile data from the generatedfabrication attributes, the profile data comprising profile shapes andcritical dimensions of structures resulting from the one or morefabrication process simulations; simulating one or more devices usingprofile data generated by the one or more simulated fabricationprocesses; and creating simulation data store instances, the instancesincluding profile data from the generated fabrication attributes,corresponding calculated signals, simulation types and associatedprocess control parameters and device attributes; wherein the simulationtypes are characterizations of the one or more simulations performed.12. The method of claim 11 wherein the one or more fabrication processessimulated include a lithography simulation and an etch simulation andwherein the one or more device simulations include an interconnectsimulation.
 13. A method of creating a profile-based simulation datastore for an integrated circuit, the method comprising: simulating oneor more devices using a selected set of input parameters, the devicesimulations generating device attributes, the set of input parametersincluding profile data of the one or more simulated devices; generatingcalculated signals with a metrology simulator, the metrology simulatorusing profile data of the one or more simulated devices; simulating oneor more circuits using the generated device attributes from the one ormore device simulations as input parameters, the circuit simulationsgenerating circuit attributes; and creating simulation data storeinstances, the instances including profile data and correspondingcalculated signals, simulation types and associated input parameters,device attributes, and circuit attributes; wherein the simulation typesare characterizations of the one or more simulations performed.
 14. Themethod of claim 13 wherein the one or more device simulations include apower device simulation and an interconnect simulation.
 15. The methodof claim 13 wherein the one or more circuit simulations include atransmission line simulation and an amplifier simulation.
 16. A methodof creating a profile-based simulation data store for an integratedcircuit utilizing one or more simulations, the method comprising:simulating one or more fabrication processes using a selected set ofprocess control parameters, the fabrication process simulationsgenerating fabrication attributes; generating calculated signals with ametrology simulator, the metrology simulator using profile data from thegenerated fabrication attributes, the profile data comprising profileshapes and critical dimensions of structures resulting from the one ormore fabrication process simulations; simulating one or more devicesusing profile data generated by the one or more simulated fabricationprocesses; simulating one or more circuits using the generated deviceattributes from the one or more device simulations as input parameters,the circuit simulations generating circuit attributes; and creatingsimulation data store instances, the instances including profile data,corresponding calculated signals, simulation types, and associatedprocess control parameters, fabrication attributes, device attributes,and circuit attributes; wherein the simulation types arecharacterizations of the one or more simulations performed.
 17. Themethod of claim 16 wherein the one or more fabrication processsimulations include a lithography simulation, the one or more devicesimulation includes an interconnect simulation, and the one or morecircuit simulation include a transmission line simulation.
 18. A methodof creating a profile-based simulation data store for an integratedcircuit, the method comprising: measuring one or more test gratings witha metrology device wherein the test gratings model the effect of anintegrated circuit design and/or fabrication process; generatingmeasured signals with the metrology device; converting the measuredsignals into profile data corresponding to the measured test gratings;simulating one or more devices using the converted profile data as a setof input parameters, the device simulations generating deviceattributes; and creating simulation data store instances, the instancesincluding profile data, corresponding measured signals, simulationtypes, and associated device attributes; wherein the simulation typesare characterizations of the one or more simulations performed.
 19. Themethod of claim 18 wherein converting the measured signals into processcontrol parameters further comprises: comparing the measured signals offthe test gratings to instances of a library of calculated signals, theinstances of the library of calculated signals having data elementscomprising calculated signals and profile data; selecting correspondingbest matching instances in the library of calculated signals; andaccessing profile data from the selected best matching instances of thelibrary of calculated signals.
 20. The method of claim 18 wherein theone or more device simulations are interconnect simulations.
 21. Themethod of claim 18 wherein measuring the test grating further comprises:designing the test gratings to capture interconnect geometricconfigurations of the integrated circuit; fabricating the designed testgratings; and measuring the fabricated test gratings with the metrologydevice.
 22. The method of claim 18 wherein the device attributes includeresistance, inductance, capacitance, potential, temperature, and currentdensity distribution of the interconnect.
 23. A method of real-time useof simulation data store, the method comprising: measuring a gratingwith a metrology device, the grating modeling an interconnect geometryof an integrated circuit, the measurement generating a measured signal;and obtaining interconnect electrical properties and/or thermalproperties corresponding to the measured signal off the grating.
 24. Themethod of claim 23 wherein obtaining interconnect electrical propertiesand/or thermal properties corresponding to the measured signal off thegrating further comprises: accessing a simulation data store, thesimulated data store storing instances having data elements comprisingsignals and device attributes, the device attributes includinginterconnect electrical properties and/or thermal properties; comparingthe measured signal to the signals in the instances of the simulationdata store; selecting a best matching instance of the simulation datastore; and accessing the interconnect electrical properties and/orthermal properties associated with the best matching instance of thesimulated data store.
 25. The method of claim 23 wherein theinterconnect electrical properties include capacitance, inductance, andresistance.
 26. A method of creating a profile-based simulation datastore for an integrated circuit utilizing a metrology simulator, themethod comprising: performing fabrication process simulations using aset of process control parameters, the fabrication process simulationsgenerating a set of fabrication attributes and a set of structureprofile data; calculating a set of simulated signals corresponding tothe set of structure profile data using a metrology simulator; andcreating instances of a simulation data store, each instance of thesimulation data store having data elements comprising profile data andcorresponding calculated signals, simulation types, and associatedprocess control parameters and fabrication attributes; wherein thesimulation types are characterizations of the simulations performed. 27.The method of claim 26 wherein the fabrication process simulation is alithography simulation.
 28. The method of claim 26 wherein thefabrication process simulation is a combined lithography and etchsimulation.
 29. The method of claim 26 wherein the fabrication processsimulation is an implantation simulation, diffusion simulation,oxidation simulation, deposition and etching simulation, chemicalmechanical polishing simulation, deposition and reflow simulation,2-dimensional process simulation, or 3-dimensional fabrication processsimulation.
 30. The method of claim 26 wherein the metrology simulatoris an optical metrology simulator.
 31. A system for creating aprofile-based simulation data store for an integrated circuit, thesystem comprising: a profiler application server configured to: comparea measured signal off a test grating in a wafer to calculated signals ininstances of a calculated signals library, the library instances storingdata elements comprising calculated signals and profile data, and selecta best matching instance of the library of calculated signals; afabrication process simulator configured to: simulate one or morefabrication processes, and generate fabrication attributes utilizingprofile data associated with the best matching instance of the libraryof calculated signals; and a simulation data store generator configuredto: create an instance of a simulation data store, the simulation datastore instance storing data elements comprising the profile data,associated measured signals, simulation types, and the associatedfabrication attributes; wherein the simulation types arecharacterizations of the one or more fabrication processes simulationsperformed.
 32. A system for creating a profile-based simulation datastore for an integrated circuit, the system comprising: a profilerapplication server configured to: compare a measured signal off a testgrating in a wafer to calculated signals in instances of a calculatedsignals library, the library instances storing data elements comprisingprofile data and associated calculated signals, and select a bestmatching instance of the library of calculated signals; a devicesimulator configured to: simulate one or more devices, and generatedevice attributes utilizing profile data associated with the bestmatching instance of the library of calculated signals; and a simulationdata store generator configured to: create an instance of a simulationdata store, the simulation data store instance storing data elementscomprising the profile data, associated measured signals, simulationtypes, and associated device attributes; wherein the simulation typesare characterizations of the one or more device simulations performed.33. A system for creating a profile-based simulation data store for anintegrated circuit, the system comprising: a profiler application serverconfigured to: compare a measured signal off a test grating in a waferto calculated signals in instances of a calculated signals library, thelibrary instances storing data elements comprising profile data andassociated calculated signals, and select a best matching instance ofthe library of calculated signals; a device simulator configured to:simulate one or more circuits, and generate circuit attributes utilizingprofile data associated with the best matching instance of the libraryof calculated signals; and a simulation data store generator configuredto: create an instance of a simulation data store, the simulation datastore instance storing data elements comprising the profile data,associated measured signals, simulation types, and associated circuitattributes; wherein the simulation types are characterizations of theone or more circuit simulations performed.
 34. A system for creating aprofile-based simulation data store for an integrated circuit, thesystem comprising: a fabrication process simulator configured to:simulate one or more fabrication processes using a selected set ofprocess control parameters, the fabrication process simulationsgenerating fabrication attributes, the fabrication attributes includingstructure profile data; a metrology simulator configured to: receive thestructure profile data from the fabrication process simulator, andgenerate calculated metrology signals using a simulated grating, thesimulated grating having a repeating structure with the same profiledata as the received structure profile data; a simulation data storegenerator configured to: create instances of a simulation data store,each simulation data store instance storing data elements comprising theprofile data, associated calculated signals, simulation types, andassociated process control parameters and fabrication attributes;wherein the simulation types are characterizations of the one or morefabrication process simulations performed.
 35. A system for creating aprofile-based simulation data store for an integrated circuit, thesystem comprising: a fabrication process simulator configured to:simulate one or more fabrication processes using a selected set ofprocess control parameters, the fabrication process simulationsgenerating fabrication attributes, the generated fabrication attributesincluding structure profile data; a metrology simulator configured to:receive the structure profile data from the fabrication processsimulator, and generate calculated metrology signals using a simulatedgrating, the simulated grating having a repeating structure with thesame profile data as the received structure profile data; a devicesimulator configured to: simulate one or more devices using the profiledata from the generated fabrication attributes; a simulation data storegenerator configured to: create instances of a simulation data store,each simulation data store instance storing data elements comprising theprofile data, associated measured signals, simulation types, andassociated process control parameters, fabrication attributes, anddevice attributes; wherein the simulation types are characterizations ofthe one or more fabrication or device simulations performed.
 36. Asystem for creating a profile-based simulation data store for anintegrated circuit, the system comprising: a fabrication processsimulator configured to: simulate one or more fabrication processesusing a selected set of process control parameters, the fabricationprocess simulations generating fabrication attributes, the generatedfabrication attributes including structure profile data; a metrologysimulator configured to: receive the structure profile data from thefabrication process simulator, and generate calculated metrology signalsoff simulated gratings, the simulated gratings having a repeatingstructure with the same profile data as the corresponding receivedstructure profile data; a device simulator configured to: simulate oneor more devices using the profile data from the generated fabricationattributes, the one or more device simulations generating deviceattributes; a circuit simulator configured to: simulate one or morecircuits using the generated device attributes from the one or moredevice simulations as input parameters, the one or more circuitsimulations generating circuit attributes; a simulation data storegenerator configured to: create instances of a simulation data store,each simulation data store instance storing data elements comprising theprofile data, associated measured signals, simulation types, andassociated process control parameters, fabrication attributes, deviceattributes, and circuit attributes; wherein the simulation types arecharacterizations of the one or more fabrication process, device orcircuit simulations performed.
 37. A system for creating a profile-basedsimulation data store for an integrated circuit, the system comprising:a metrology simulator configured to: generate calculated metrologysignals using input profile data; a device simulator configured to:simulate one or more devices using the input profile data, the one ormore device simulations generating device attributes; a circuitsimulator configured to: simulate one or more circuits using thegenerated device attributes from the one or more device simulations asinput parameters, the one or more circuit simulations generating circuitattributes; a simulation data store generator configured to: createinstances of a simulation data store, each simulation data storeinstance storing data elements comprising the profile data, associatedmeasured signals, simulation types, and associated device attributes andcircuit attributes; wherein the simulation types are characterizationsof the one or more device or circuit simulations performed.
 38. A systemfor real-time determination of profile-based simulation information foran integrated circuit, the system comprising: a query device configuredto: send a query comprising type of inquiry for profile-based simulationdata and query given data, and receive a response to the query; asimulation data store server configured to: process the query andformulate the response to the query; and a simulation data storeconfigured to: store instances having data elements comprising profiledata, signals, and process control parameters, and fabricationattributes; wherein the simulation data store server, receiving a queryfrom the query device, accesses selected instances of the simulationdata store, the selection of the instances of the simulation data storedetermined by the type of inquiry and query given data, formulates theresponse to the query, and transmits the response to the query device.39. The inquiry system of claim 38 wherein the query device is ametrology system and the query given data is a measured diffractedsignal generated by the metrology system.
 40. The inquiry system ofclaim 39 wherein the query given data is the measured diffracted signaland the response to the query comprises interconnect electrical deviceattributes from the selected instances of the simulation data store. 41.The inquiry system of claim 38 wherein the query given data are processcontrol parameters comprising focus and numerical aperture and theresponse to the query are fabrication attributes comprising sidewallangle and top critical dimension from the selected instances of thesimulation data store.
 42. The inquiry system of claim 38 wherein thequery device, the simulation data store, and the simulation data storeserver are contained in one logical device.
 43. The inquiry system ofclaim 42 wherein the one logical device is coupled to one or moreintegrated circuit fabrication process devices.
 44. The inquiry systemof claim 43 wherein the integrated circuit fabrication process device isa lithography unit.
 45. The inquiry system of claim 43 wherein theintegrated circuit fabrication process device is a photoresist strippingunit.
 46. A computer-readable storage medium containing computerexecutable code to provide a response to an inquiry regardingprofile-based simulation data of an integrated circuit by instructingthe computer to operate as follows: receiving a query from a querydevice, the query comprising a type of inquiry and query given data;accessing a selected one or more instances of a simulation data store,the selection determined by the type of inquiry and query given data;and formulating a response to the query and transmitting the response tothe query device; wherein the simulation data store stores instanceshaving data elements comprising structure profile data, fabricationattributes, signals, and process control parameters.
 47. Acomputer-readable storage medium containing computer executable code tocreate a profile-based simulation data store for an integrated circuitby instructing the computer to operate as follows: performing afabrication process simulation using process control parameters, thefabrication process simulation generating fabrication attributes andstructure profile data; calculating a simulated signals for thestructure profile data using a metrology simulator; and creating aninstance of a simulation data store, the instance of the simulation datastore having data elements comprising the structure profile data, theassociated fabrication attributes, the simulated signals, and theprocess control parameters.
 48. A computer-readable storage mediumcontaining computer executable code to create a profile-based simulationdata store for an integrated circuit by instructing the computer tooperate as follows: simulating one or more devices using a selected setof input parameters, the device simulations generating deviceattributes, the set of input parameters including profile datacorresponding to the one or more simulated devices; generatingcalculated signals with a metrology simulator, the metrology simulatorusing profile data corresponding to the one or more simulated devices;and creating simulation data store instances, the instances includingcalculated metrology signals, profile data, simulation types, processcontrol parameters, and fabrication attributes; wherein the simulationtypes are characterizations of the one or more simulations performed.49. A computer-readable storage medium containing computer executablecode to create a profile-based simulation data store for an integratedcircuit by instructing the computer to operate as follows: simulatingone or more circuits using a selected set of input parameters, a circuithaving one or more devices, the circuit simulations generating circuitattributes, the set of input parameters including profile datacorresponding to the one or more devices of the simulated one or morecircuits; generating calculated signals with a metrology simulator, themetrology simulator using profile data corresponding to the one or moredevices of the simulated one or more circuits; and creating simulationdata store instances, the instances including calculated metrologysignals, profile data, simulation types, process control parameters, andcircuit attributes; wherein the simulation types are characterizationsof the one or more simulations performed.
 50. A method of providing aservice for creating and using a profile-based simulation data store foran integrated circuit, the method comprising: contracting by a clientand a vendor, for the client to remunerate the vendor for the use ofsystems, processes, and procedures to create and use a profile-basedsimulation data store; and providing by the vendor to the client accessto systems, processes, and procedures to create and use a profile-basedsimulation data store, the simulation data store storing instanceshaving data elements comprising profile data, metrology signals, processcontrol parameters, and fabrication attributes.
 51. A profile-basedsimulation data store for an integrated circuit, the data storecomprising: one or more instances of a simulation data store, eachinstance of the simulation data store including profile data, associatedmetrology signal and one or more simulation data segments; wherein themetrology signal corresponds to an integrated circuit structure with aprofile characterized by the profile data; wherein each data segmentincludes simulation type, associated process control parameters orassociated simulation input parameters, and associated simulationattributes; and wherein the associated simulation attributes comprisesdata determined by the simulation using the process control parametersor the associated simulation input parameters.
 52. The simulation datastore of claim 51 wherein the simulation attributes are fabricationprocess attributes, device attributes, or circuit attributes dependingon the simulation type.